Food for thought – some Tuesday “did ya know”

September 11, 2012

So – do you guys remember my Sunday post about coffee?  And I said that I wanted to take a closer look at how they take a naturally caffeinated product and make it decaf?  Decaf coffee contains up to 10% caffeine, so any extraction method has to remove at least 90% of the caffeine from the bean.   Its pretty easy to add to something, but how do you extract a chemical from a solid bean?

Well, I did some digging around and it turns out there are three general methods.  Which is a bit nicer than the original Benzene extraction method they used to use.

So how DO they get the caffeine out?

The first and probably the most natural of the three methods, appropriately referred to as the natural method, is the Water Method.   Its a bit of an intricate process of “battery extraction”.   The key to this is the water that runs over the fresh, green coffee beans (pre-roast) – solubilizes the caffeine in the beans and is extracted from the bean into the water.   The oils from the coffee beans helps to extract the caffeine from the beans.   Here’s the thing about that water though.  That water is technically a decaf coffee brew.  The circulating water has been brewed with coffee beans, essentially creating a caffeinated brew.   That brew is then run over charcoal that has been coated with a carbohydrate, usually sucrose, that extracts the caffeine from the brew.  That decaffeinated beverage is the water used to extract caffeine from the green coffee beans I mentioned above.   Kind of makes your eyes swim, right?

While the water method is the least, invasive, we’ll say – its also the least specific for caffeine and only removes up to 96% of caffeine from the coffee beans.

The second two methods are the direct solvent method and the supercritical carbon dioxide extraction method (ooooOOOOOooooo).  If both of these sound a little scarier than the water method, its sort’ve true, they’re both harsher than caffeine extraction by water.

The direct solvent usually employs the use of a chemical solvent to extract the caffeine from the coffee beans.  The three most common solvents are methylene chloride, coffee oil or ethyl acetate.  Ethyl acetate is the same ester that’s found naturally in fruits like bananas.  Similar to the water extraction method, the solvent is circulated over the green coffee beans and recaptured. The beans are cleaned of any residual solvent by steaming and the process is repeated until the desired level of extraction is achieved.   Solvents are more specific for caffeine than water and can extract 96-97% of the caffeine.

The last extraction method, supercritical carbon dioxide extraction is essentially the same as the solvent method, only it uses – you guessed it…carbon dioxide, circulating at very high pressures.  These high pressures give the gas “supercritical properties” (and a cape?? haha).   The gas takes on the caffeine, then circulated through those same carbo coated charcoals in a column to remove the caffeine from the gas, so it can be recirculated to repeat the process.  Its an expensive method, but extremely efficient, extracting up to 98% of the caffeine and has the added bonus of being naturally abundant.


So.  There you have it.  Honestly, when reading these my first thought was “yikes…”  A lot of times, coffee isn’t about the caffeine for me, its about the taste and the rituatl.  So sometimes, when I carve the taste of coffee, but know I’ve reached my limit for caffeine, I opt for a cup of decaf, to prolong that single moment of enjoying a hot cup of coffee.  But now, I’m not so sure.   I dunno, would you guys want to drink decaf, knowing the different processes it takes to make it?    I think of it like soda, I prefer to have a little bit of the real stuff every now and then, than a lot of the “fake stuff” all the time.    Although, in the grand scheme of things, is it so bad?  Hard to tell.

Just some food for thought.




words cannot express.


see it here

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